>> because laws are easy to un- do. we could have the experience now with affordable health care act. if you put it in the constitution before it ever been a repeal of an imminent, it was there for ever and beyond the reach -- beyond being affected by the rebels and waves of partisan politics. >> prohibition is based on the 18th amendment prohibition about col. but as the constitutional hope for prohibition of any drugs? -- what is the constitutional prohibition of any drugs? >> sometimes the federal government can condition states accepting money from the federal government on states prohibiting. south the cosa -- dakota, a big case about the drinking age. it tells state if you want this money, yet to make certain changes about what eight people can legally consume alcohol. everybody in these places can or cannot do something. some of it is a contract. they tell the state we have the money for you, if you want it, you have to tell your citizens to do certain things. [inaudible] >> it is based on the commerce clause. th